isomorphic positions are positions in a problem's paths where different moves lead to the same position. to save effort for the problem creator, the site automatically understands how to transpose from one isomorphic position to another.

starting today, when in solving mode, the Java applet and the Javascript version are now both using a pre-expanded version of the SGF. the Javascript code never was able to handle isomorphic positions, and this is better for export too.

I like it, especially when solving a problem wrong, now it is easier to go back one move and try to continue (in the old version it was sometimes weird because the undo put you on another branch of the tree).The only drawback i see is that now, there are a lot more links in the solution window, making it a bit thick to read. I don't know, if it's possible, drawing only the link between first isomorphic nodes and not drawing links for subsequent nodes would makes it clearer.